甜高粱秆固态发酵制取酒精的研究

甜高粱秆液态发酵中,存在着榨汁难,糖分损失严重等问题.采用固态发酵的方式,进行了甜高粱发酵酒精的研究,确定了发酵过程中发酵时间、接种率、初始pH、营养盐等因素的优化方案.将总糖含量为13%,含水量约80%的甜高粱秆直接绞碎至约0.3cm长,在最佳优化条件下35℃固态发酵24h,酒精的理论产率为0.332g乙醇/g甜高梁秆干料,实际得率为0.298g乙醇/g甜高梁秆干料(达到理论产率的89.8%),生产1t酒精需要3.01t的甜高粱秆干料.     

甜高粱秸秆发酵菌种的诱变育种及其固态发酵工艺的研究

以耐酒精高活性干酵母为原始出发菌株进行60Co-γ辐射诱变处理,经逐级筛选和300g甜高粱秸秆固态发酵,确定H13为最佳诱变菌种;并对H13菌株的甜高粱秸秆固态发酵工艺进行研究,结果表明,粉碎后的甜高粱秸秆300g,5‰的菌体接种量、68％的基质含水量、36℃条件下发酵60h,乙醇产率达6.4g/100g鲜秸秆.     

甜高梁秸秆固态发酵生产燃料乙醇的工艺研究

利用选育的耐酸耐高温酵母Q-10,采用甜高粱秸秆固态发酵生产燃料乙醇。当接种量为5％、发酵温度34％、发酵起始pH4．0、糖化酶和纤维素酶用量分别为50U／g原料和20U／g原料、发酵周期4d时,乙醇产量达到6．5％（v／v）。小试试验乙醇产量达到6．4％（v／v）,工业试验乙醇产量达到6．0％（v／v）。     

甜高粱茎秆汁液酒精发酵及其经济可行性研究

研究了（NH4）SO4,KH2PO4和MgSO4对甜高粱茎秆汁液酒精发酵的影响,并对甜高粱茎秆汁液酒精发酵的经济可行性进行了分析。结果表明,（NH4）2SO4和KH2PO4的添加有利于提高甜高粱汁酒精发酵的产量和产率,MgSO4的添加无益于酒精产量的提高;在（NH4）2SO4和KH2PO4的用量分别为2g／L和5g／L时,终酒精浓度为94．5g／L,酒精产率为0．44。经济性分析表明,甜高粱茎秆汁液酒精发酵生产酒精可以获得很好的经济效益。     

甜高粱秆固态发酵失重与温度的相互关系

利用实验室自行筛选的高效酵母菌株TSH-SC-1,以甜高粱秆为原料进行固态发酵制燃料乙醇,在24 h内总糖转化率为95.6 %,发酵料中残糖浓度为0.45 g/100 g湿料,乙醇得率为理论值的84.9 %.通过计算机实时采集和记录发酵过程中固态物料的温度和重量的数据,并且通过数值求导得到发酵过程中两者变化的速率.结果表明,两者均能够比较一致地反映固态发酵过程的内在变化,因而温度变化的实时数据可以作为过程监控和诊断的依据.另外,由发酵过程温度变化、散热数据和乙醇得率,估算了固态发酵生成每摩尔乙醇的放热量为56 kJ,该数据可以用于固态发酵反应器的工程设计和优化放大.     

以木糖为原料的酒精发酵研究

对产朊假丝酵母山2．120，嗜鞣管囊酵母As2．1585和粗糙脉孢菌出3．1598等3种菌株在以木糖为惟一碳源的培养基上的生长和发酵情况进行研究．结果表明：嗜鞣管囊酵母As2．1585可以很好地发酵木糖生产酒精，在28℃，150r／min条件下，摇瓶发酵摩尔分数为3％的木糖72h，酒精体积分数达到最大值0．63％，木糖利用率为91．67％，每100g木糖产酒精22．9g，为理论酒精产率的48．7％。     

玉米秸秆水解液生产燃料酒精的研究

通过对稀硫酸预处理玉米秸秆水解液发酵生产燃料酒精各因素进行分析，初步确定了利用奥默毕赤氏酵母的最适发酵条件：发酵温度为36℃，时间为60h，通风量为0．081／min,初始还原糖浓度为74．0g／1。在最适发酵条件下，乙醇产率为0．327g／g。在73．96g／1的水解液中添加20g／1葡萄糖会导致酵母发酵过程出现“二次生长”现象。     

戊糖和己糖共发酵生产燃料乙醇发酵体系优化研究

研究了戊糖和己糖共发酵生产燃料乙醇发酵体系的影响因素．正交试验获得的最佳发酵体系为：在基础发酵培养基中添加φ（Tween-80）=0．025％，ρ（聚乙烯醇4000）=100g／L，p（L-谷氨酰胺）：0．625g／L．在此条件下，发酵至72h时，乙醇产率为43、56％.     

酶制剂的添加对早籼稻谷生料发酵生产酒精的影响

对早籼稻谷生料发酵生产酒精进行了研究。结果表明：淀粉酶、纤维素酶、酸性蛋白酶、果胶酶的添加对酒精发酵没有明显效果。糖化酶最佳添加量为225U／g原料，最佳料液比为1：3．5，300℃120h，酒精度达9．0％(v／v)，残总糖为1．20％，淀粉出酒率达51．28％。     

混合菌同步糖化共发酵造纸污泥产乙醇

对酿酒酵母（Saccharomyces cerevisiae）与重组大肠杆菌K011（Escherichia coli）混合菌同步糖化共发酵造纸污泥产乙醇进行了初步研究。在底物浓度为50g／L时,通过单因素实验和正交实验获得乙醇发酵的最佳条件：纤维素酶添加量25FPU／g底物,接种量为6％,酿酒酵母与重组大肠杆菌K011接种比例为1：1（细胞干重初始浓度分别为1．0g／L和0．3g／L左右）。发酵72h后,乙醇浓度为5．71g／L,产率达到0．114g乙醇／g污泥,达到理论值的42．5％。分别用酿酒酵母、K011单菌种发酵与双菌株组合发酵对比结果表明,混合菌发酵效果明显优于单菌种发酵。     

Reliable identification of grapevine rootstock varieties using RAPD PCR on woody samples

Since grapevine ( Vitis spp .) rootstock material is being traded increasingly as disbudded woody material a lack of distinctive morphological features on such material necessitates an alternative and reliable means of identification. Methods described here were developed for rapid and efficient extraction of DNA from woody samples rich in phenolic compounds and polysaccharides, and for subsequent identification of varieties by RAPD PCR. Using these methods, and with the application of only one selected RAPD primer, we were able to differentiate sixteen rootstock varieties, including the seven varieties most commonly used in Germany. Problems commonly encountered with reproducibility of RAPD patterns were avoided by choosing primers with a dinucleotide sequence and a high G/C content that allowed a rather high annealing temperature of 45°C. Methods described here should also be useful for other horticultural crops, especially those with woody tissues rich in phenolic compounds and polysaccharides.     

An internet compendium of analytical methods and spectroscopic information for monomers and additives used in food packaging plastics

An internet website (http://cpf.jrc.it/smt/) has been produced as a means of dissemination of methods of analysis and supporting spectroscopic information on monomers and additives used for food contact materials (principally packaging). The site which is aimed primarily at assisting food control laboratories in the European Union contains analytical information on monomers, starting substances and additives used in the manufacture of plastics materials. A searchable index is provided giving PM and CAS numbers for each of 255 substances. For each substance a data sheet gives regulatory information, chemical structures, physico-chemical information and background information on the use of the substance in particular plastics, and the food packaging applications. For monomers and starting substances (155 compounds) the infra-red and mass spectra are provided, and for additives (100 compounds); additionally proton NMR are available for about 50% of the entries. Where analytical methods have been developed for determining these substances as residual amounts in plastics or as trace amounts in food simulants these methods are also on the website. All information is provided in portable document file (PDF) format which means that high quality copies can be readily printed, using freely available Adobe Acrobat Reader software. The website will in future be maintained and up-dated by the European Commission's Joint Research Centre (JRC) as new substances are authorized for use by the European Commission (DG-ENTR formerly DGIII). Where analytical laboratories (food control or other) require reference substances these can be obtained free-ofcharge from a reference collection housed at the JRC and maintained in conjunction with this website compendium.     

Aroma characterization of various apricot varieties using headspace–solid phase microextraction combined with gas chromatography–mass spectrometry and gas chromatography–olfactometry

The characterization of the aromatic profile of several apricot cultivars with molecular tracers in order to obtain objective data concerning the aromatic quality of this fruit was undertaken using headspace–solid phase microextraction (HS–SPME). Six apricot cultivars were selected according to their organoleptic characteristics: Iranien, Orangered, Goldrich, Hargrand, Rouge du Roussillon and A4025. The aromatic intensity of these varieties measured by HS–SPME–Olfactometry were defined and classified according to the presence and the intensity of grassy, fruity and apricot like notes. In the six varieties, 23 common volatile compounds were identified by HS–SPME–GC–MS. Finally, 10 compounds, ethyl acetate, hexyl acetate, limonene, β-cyclocitral, γ-decalactone, 6-methyl-5-hepten-2-one, linalool, β-ionone, menthone and (E)-hexen-2-al were recognized by HS–SPME–GC–O as responsible of the aromatic notes involved in apricot aroma and considered as molecular tracers of apricot aromatic quality which could be utilized to discriminate apricot varieties.     

Tests of potential functional barriers for laminated multilayer food packages. Part I: Low molecular weight permeants

The advent of the functional barrier concept in food packaging has brought with it a requirement for fast tests of permeation through potential barrier materials. In such tests it would be convenient for both foodstuffs and materials below the functional barrier (sub-barrier materials) to be represented by standard simulants. By means of inverse gas chromatography, liquid paraffin spiked with appropriate permeants was considered as a potential simulant of sub-barrier materials based on polypropylene (PP) or similar polyolefins. Experiments were performed to characterize the kinetics of the permeation of low molecular weight model permeants (octene, toluene and isopropanol) from liquid paraffin, through a surrogate potential functional barrier (25 μm-thick oriented PP) into the food simulants olive oil and 3% (w/v) acetic acid. These permeation results were interpreted in terms of three permeation kinetic models regarding the solubility of a particular model permeant in the post-barrier medium (i.e. the food simulant). The results obtained justify the development and evaluation of liquid sub-barrier simulants that would allow flexible yet rigorous testing of new laminated multilayer packaging materials.     

Chlorohydrins of bisphenol A diglycidyl ether (BADGE) and of bisphenol F diglycidyl ether (BFDGE) in canned foods and ready-to-drink coffees from the Japanese market

BADGE.2HCl and BFDGE.2HCl were determined in 28 samples of ready-to-drink canned coffee and 18 samples of canned vegetables (10 corn, 5 tomatoes and 3 others), all from the Japanese market. HPLC was used as the principal analytical method and GCMS for confirmation of relevant LC fractions. BADGE.2HCl was found to be present in one canned coffee and five samples of corn, BFDGE.2HCl in four samples of canned tomatoes and in one canned corn. No sample was found which exceeded the 1mg/kg limit of the EU for the BADGE chlorohydrins. However the highest concentration was found for the sum of BFDGE.2HCl and BFDGE.HCl.H₂O at a level of 1.5mg/kg. A Beilstein test confirmed that all cans containing foods contaminated with BADGE.2HCl or BFDGE.2HCl had at lest one part coated with a PVC organosol.     

European priorities for research to support legislation in the area of food contact materials and articles

A strong science base is required to underpin the planning and decision-making process involved in determining future European community legislation on materials and articles in contact with food. Significant progress has been made in the past 5 years in European funded work in this area, with many developments contributing to a much better understanding of the migration process, and better and simpler approaches to food control. In this paper this progress is reviewed against previously identified work-areas (identified in 1994) and conclusions are reached about future requirements for R&D to support legislation on food contact materials and articles over the next 5 or so years.     

Analysis of benzo[a]pyrene in spiked fatty foods by second derivative synchronous spectrofluorimetry after microwave-assisted treatment of samples

A simple, rapid and inexpensive method has been developed for the determination of benzo[a     

The development of reference materials for paralytic shellfish poisoning toxins in lyophilized mussel. II: Certification study

This paper describes the second part of a project undertaken to develop certified mussel reference materials for paralytic shellfish poisoning toxins. In the first part two interlaboratory studies were undertaken to investigate the performance of the analytical methodology for several PSP toxins, in particular saxitoxin and decarbamoyl-saxitoxin in lyophilized mussels, and to set criteria for the acceptance of results to be applied during the certification exercise. Fifteen laboratories participated in this certification study and were asked to measure saxitoxin and decarbamoyl-saxitoxin in rehydrated lyophilized mussel material and in a saxitoxin-enriched mussel material. The participants were allowed to use a method of their choice but with an extraction procedure to be strictly followed. The study included extra experiments to verify the detection limits for both saxitoxin and decarbamoyl-saxitoxin. Most participants (13 of 15) were able to meet all the criteria set for the certification study. Results for saxitoxin.2HCl yielded a certified mass fraction of <0.07 mg/kg in the rehydrated lyophilized mussels. Results obtained for decarbamoyl-saxitoxin.2HCl yielded a certified mass fraction of 1.59+/-0.20 mg/kg. The results for saxitoxin.2HCl in enriched blank mussel yielded a certified mass fraction of 0.48 +/- 0.06 mg/kg. These certified reference materials for paralytic shellfish poisoning toxins in lyophilized mussel material are the first available for laboratories to test their method for accuracy and performance.     

Announcing a new international peer-reviewed journal:Food Science and Human Wellness now accepting manuscript submission in English

<正>We are pleased to announce the launch of a new international peer-reviewed journal-Food Science and Human Wellness,ISSN 2213-4530,which is an open access journal,produced and hosted by Elsevier B.V.on behalf of Beijing Academy of Food Sciences.Food Science and Human Wellness is an international peer-reviewed English journal that provides a forum for the dissemination of the